// useful key codes
const
KC_ESCAPE = 27,
KC_RETURN = 13,
KC_UP = 38,
KC_DOWN = 40,
KC_LEFT = 37,
KC_RIGHT = 39,
KC_DELETE = 46,
KC_BACKSPACE = 8,
KC_SHIFT = 16,
KC_CTRL = 17,
KC_ALT = 18,
KC_CAPSLOCK = 20,
KC_TAB = 9,
KC_END = 35,
KC_HOME = 36,
KC_F1 = 112,
KC_F2 = 113,
KC_F3 = 114,
KC_F4 = 115,
KC_F5 = 116,
KC_F6 = 117,
KC_F7 = 118,
KC_F8 = 119,
KC_F9 = 120,
KC_F10 = 121,
KC_F11 = 122,
KC_F12 = 123,
KC_ZERO = 48,
KC_ONE = 49,
KC_TWO = 50,
KC_THREE = 51,
KC_FOUR = 52,
KC_FIVE = 53,
KC_SIX = 54,
KC_SEVEN = 55,
KC_EIGHT = 56,
KC_NINE = 57;
